Auto lock for catheter handle

ABSTRACT

The present invention is a catheter actuation handle for deflecting a distal end of a tubular catheter body, the handle including an auto-locking mechanism. The handle comprises upper and lower grip portions, an actuator, and an auto-locking mechanism. The auto-locking mechanism is adapted to hold a deflected distal end of the catheter in place without input from the operator. When the distal end of the catheter is deflected from its zero position, it typically will seek a return to its zero position, and as a result exerts a force on the actuator. The auto-locking mechanism acts by providing a second force that resists this force from the distal end and holds the distal end in place. As a result, the operator does not need to maintain contact with the buttons to maintain the distal end  18  in a set position once placed there by actuating the actuator.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/311,525, filed 23 Jun. 2014, (the '525application), which is a continuation of U.S. patent application Ser.No. 11/646,744, filed 27 Dec. 2006 (the '744 application), now U.S. Pat.No. 8,777,929, issued 15 Jul. 2014, which claims the benefit of U.S.provisional application No. 60/801,464, filed 17 May 2006 (the '464application). The '744 application is also a continuation-in-part ofU.S. application Ser. No. 11/170,550, filed 28 Jun. 2005, now U.S. Pat.No. 7,465,288, issued 16 Dec. 2008 (the '550 application), and claimsthe benefit of U.S. Patent Cooperation Treaty application no.PCT/US2006/025082, filed 27 Jun. 2006 (the '082 application). The '525,the '744, the '464, the '550, and the '082 applications are herebyincorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION a. Field of the Invention

The instant invention relates to catheters and sheaths and methods ofusing catheters and sheaths. In particular, the instant inventionrelates to steerable catheter or sheath control handles and methods ofmanufacturing and using such handles.

b. Background Art

Catheters that have flexible tubular bodies with deflectable distal endsand control handles for controlling distal end deflection are used formany noninvasive medical procedures. For example, catheters havingconductive electrodes along the distal ends of their bodies are commonlyused for intra-cardiac electrophysiology studies. The distal portion ofsuch a catheter is typically placed into the heart to monitor and/orrecord the intra-cardiac electrical signals during electrophysiologystudies or during intra-cardiac mapping. The orientation orconfiguration of the catheter distal end is controlled via an actuatorlocated on a handle outside of the body, and the electrodes conductcardiac electrical signals to appropriate monitoring and recordingdevices that are operatively connected at the handle of the catheter.

Typically, these catheters include a generally cylindrical electricallynonconductive body. The main body includes a flexible tube constructedfrom polyurethane, nylon or other electrically non-conductive flexiblematerial. The main body further includes braided steel wires or othernon-metallic fibers in its wall as reinforcing elements. Each electrodehas a relatively fine electrically conductive wire attached thereto andextending through the main body of the catheter. The conductive wireextends from the distal end to a proximal end where electricalconnectors such as plugs or jacks are provided to be plugged into acorresponding socket provided in a recording or monitoring device.

The distal portion of the main body is selectively deformed into avariety of curved configurations using the actuator. The actuator iscommonly internally linked to the distal portion of the catheter by atleast one actuation wire. Some catheters employ a single actuation wire,which is pulled (i.e., placed in tension) by the actuator in order tocause the distal portion of the main body to deform. Other cathetershave at least two actuation wires, where the actuation of one wire(i.e., placing one wire in tension) results in the other wire goingslack (i.e., the wire does not carry a compressive load). In suchcatheters, where the actuation wires are not adapted to carrycompressive loads (i.e., the actuation wires are only meant to be placedin tension), the actuation wires are commonly called pull or tensionwires.

To deform the distal end of the catheter into a variety ofconfigurations, a more recent catheter design employs a pair ofactuation wires that are adapted such that one of the actuation wirescarries a compressive force when the other actuation wire carries atensile force. In such catheters, where the actuation wires are adaptedto carry both compressive and tension loads, the actuation wires arecommonly called push/pull or tension/compression wires and thecorresponding catheter actuators are called push-pull actuators. U.S.Pat. No. 5,861,024 to Rashidi, which issued Jan. 19, 1999, isrepresentative of a push-pull actuator of this type, and the detailsthereof are incorporated herein by reference.

While many of the existing catheter actuators provide precise operationand good flexibility in movement of the distal portion of the body, theexisting actuators often offer a range of distal portion displacementthat is less than desirable. In other words, the amount of push/pull ofthe actuation wires (i.e., the steering travel) is often inadequate forthe medical procedure being performed. The inadequacy of the steeringtravel typically results from the generally limited size of the actuatorbody, which is usually sized for receipt and manipulation between thethumb and index finger of a user's hand. Accordingly, a need exists toprovide an improved actuating assembly for a catheter that increases theamount of steering travel associated with the actuator.

Similarly, once the distal portion has reached a desired position, thephysician must either hold the catheter and the actuator in position tokeep the distal portion in the desired position, or the handle of thecatheter requires the physician to take a conscious step to maintain thedistal portion of the catheter at the desired position. Accordingly, aneed exists to provide an improved catheter and actuating assembly for acatheter that automatically holds the distal end of the catheter in thedesired position. There is also a need in the art for a method ofmanufacturing and using such a catheter.

BRIEF SUMMARY OF THE INVENTION

The present invention is a catheter actuation handle for deflecting adistal end of a tubular catheter body, the handle including anauto-locking mechanism. The handle includes a grip portion, an actuator,and an auto-locking mechanism. The auto-locking mechanism is adapted tohold a deflected distal end of the catheter in place without input fromthe operator. As a result, the operator does not need to maintaincontact with the buttons to maintain the distal end in a set positiononce placed there by actuating the actuator.

The auto-locking mechanism can include one or more washers, a bushing, ascrew, and a base for receiving the screw. The one or more washers canbe the same or different.

The bushing can be constructed of a polymer, a metal, stainless steel,or brass. The screw can be any type of screw, bolt, or connection means,including, preferably, a hex-head screw.

The auto-locking mechanism can further include a tensioning member. Thetensioning member can be a Belleville washer or a spring.

The auto-locking mechanism can be a grip activated locking mechanism, ora friction wheel.

The vertical load path of the auto-locking mechanism can exclude thegripping portions or body of the catheter handle.

The present invention also includes a catheter system including acatheter with a catheter shaft with proximal and distal portions, ahandle with an actuator and an auto-locking mechanism attached to theproximal portion of the catheter. The handle is adapted to hold theactuator in a position set by an operator. The catheter system can alsoinclude a second actuator and a second auto-locking mechanism.

The aspects, features, details, utilities, and advantages of the presentinvention will be apparent from reading the following description andclaims, and from reviewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the catheter (or sheath) of the presentinvention.

FIG. 2 is an isometric view of the handle with the upper and lower gripportions separated and the first actuation mechanism exploded to betterillustrate its various components.

FIG. 3 is an exploded isometric view of the gear assembly.

FIG. 4 is a top plan view of a first embodiment of the first actuationmechanism mounted in the proximal portion of the lower grip portion,wherein the first and second actuation wires are received in theirrespective holes in the wire blocks.

FIG. 5 is an enlarged plan view of the gear assembly with the topportions of the wire blocks removed to better illustrate the gearingarrangement.

FIG. 6 is a bottom plan view of the handle with the lower grip portionremoved to reveal portions of the first and second actuation mechanisms.

FIG. 7 is the same view depicted in FIG. 4, except of a secondembodiment of the first actuator.

FIG. 8 is the same view depicted in FIG. 5, except of the secondembodiment of the first actuator.

FIG. 9 is the same view depicted in FIG. 6, except of the secondembodiment of the first actuator.

FIG. 10 is an isometric view of the handle with the upper and lower gripportions separated and the second actuation mechanism exploded to betterillustrate its various components.

FIG. 11 is a top plan view of the second actuation mechanism mounted inthe lower grip portion with the upper grip portion removed.

FIG. 12 is an isometric view of an auto-lock mechanism with theauto-lock mechanism exploded to better illustrate its variouscomponents.

FIG. 12A is side cutout view of the auto-lock mechanism of FIG. 12.

FIG. 12B is side cutout view of a modification of the auto-lockmechanism of FIG. 12.

FIG. 12C is side cutout view of a modification of the auto-lockmechanism of FIG. 12.

FIG. 13A is side cutout view of a modification of the auto-lockmechanism of FIG. 12.

FIG. 13B is side cutout view of a modification of the auto-lockmechanism of FIG. 12.

FIG. 13C is side cutout view of a modification of the auto-lockmechanism of FIG. 12.

FIG. 14 is an isometric view of a second auto-lock mechanism with theauto-lock mechanism exploded to better illustrate its variouscomponents.

FIG. 15 is an isometric view of a variation of the second auto-lockmechanism with the auto-lock mechanism exploded to better illustrate itsvarious components.

FIG. 15A is an isometric view of a variation of the second auto-lockmechanism with the auto-lock mechanism exploded to better illustrate itsvarious components.

FIG. 15B is an isometric view of a variation of the second auto-lockmechanism with the auto-lock mechanism exploded to better illustrate itsvarious components.

FIG. 16 is an isometric view of a third auto-lock mechanism with theauto-lock mechanism exploded to better illustrate its variouscomponents.

FIG. 17 is an isometric view of a fourth auto-lock mechanism with theauto-lock mechanism exploded to better illustrate its variouscomponents.

FIG. 18 is an isometric view of a fifth auto-lock mechanism with theauto-lock mechanism exploded to better illustrate its variouscomponents.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is an isometric view of the catheter 10 of the present invention.Throughout this specification, the term catheter is meant to include,without limitation, catheters, sheaths, and similar medical devices. Asshown in FIG. 1, the catheter 10 can include an elongated flexiblegenerally cylindrical hollow body 12 and an ergonomically shapedactuation handle 14 coupled to a proximal end 16 of the body 12. Theactuation handle 14 is adapted to control the deflection of adeflectable distal end 18 of the body 12.

In one embodiment, as taught in U.S. patent application Ser. No.11/170,550 to Dudney et al., which was filed on Jun. 28, 2005 and ishereby incorporated in its entirety into this application, the catheter10 is advantageous for several reasons. First, the actuation handle 14has a novel rack and pinion actuation mechanism that providessignificantly increased steering travel of the distal end 18 of the body12, as compared to prior art actuation handles. Second, the actuationmechanism is configured such that it does not compress the actuationwires. Third, the actuation mechanism is configured such that theactuation force perceived by a user is minimized and generally constantover the full range of displacement, as compared to prior art actuationmechanisms. Fourth, when the body 12 includes three actuation wiresextending through the body 12 from the distal end 18 to the actuationhandle 14, the handle has a second actuation mechanism that isconfigured to actuate the third actuation wire.

As shown in FIG. 1, the actuation handle 14 can include a first actuator20, upper and lower buttons 22 a, 22 b of a second actuator, upper andlower grip portions 24 a, 24 b, an electrical plug 26 at the proximalend of the handle 14, and a strain relief 28 at the distal end of thehandle 14. The upper and lower grip portions 24 a, 24 b define a space29 that extends laterally through the grip portions 24 a, 24 b. Thefirst actuator 20 is pivotally coupled to the grip portions 24 a, 24 band resides in the space 29. The first actuator 20 may pivotallydisplace laterally relative to the grip portions 24 a, 24 b through thespace 29. Such pivotal displacement of the first actuator 20 allows auser to bi-directionally deflect the distal end 18 of the body 12.

The upper and lower buttons 22 a, 22 b of the second actuator 22 areslideably coupled to their respective grip portions 24 a, 24 b in such amanner that they may slideably displace along their respective gripportions 24 a, 24 b in a direction that is generally parallel to thelongitudinal axis of the handle 14. Such slideable displacement of thebuttons 22 a, 22 b of the second actuator 22 allows a user to deflectthe distal end 18 of the body 12 in a third direction. For example, asindicated in FIG. 1, in one embodiment where the distal end 18 forms aloop or lariat, the first actuator 20 causes the distal end 18 todeflect bi-directionally right or left, and the buttons 22 a, 22 b ofthe second actuator 22 cause the distal end 18 to increase or decreasethe diameter of its loop or lariat. In another embodiment, as taught inU.S. patent application Ser. No. 10/784,511 to Rashidi, which was filedon Feb. 23, 2004 and is hereby incorporated in its entirety into thisapplication, the first actuator 20 causes the distal end 18 tobi-directionally loop and to increase or decrease the extent to whichthe distal end 18 loops. The buttons 22 a, 22 b of the second actuator22 cause the loop or lariat formed by the distal end 18 to nod ordeflect.

As illustrated in FIG. 1, the distal end 18 of the body 12 can include aplurality of spaced electrodes 30. Each electrode 30 is connected to afine electrical conductor wire that extends to the electrical plug 26through the body 12, the strain relief 28, and the handle 14. Theelectrical plug 26 is adapted to be connected to a device, such as arecording, monitoring, or RF ablation device. While a variety ofmaterial can be used to construct body 12, it is typically constructedof polyurethane, nylon or any suitable electrically non-conductivematerial. The body 12 serves as at least a portion of the bloodcontacting segment of the catheter 10 and is vascularly inserted into apatient by methods and means well known in the art.

The actuation wires can be any of the actuation wire types known in theart. They can be pull or tension wires (i.e., the actuation wires arenot adapted to support a compressive load). They can also be configuredsuch that the actuation wires are pull/push or tension/compression wires(is., the actuation wires are adapted to support a compressive load).Thus, in the context of the first and second actuation wires, when oneactuation wire is placed in tension, the other actuation wire will carrya compressive load. The actuation wires can be formed from a superelastic Nitinol wire or another suitable material. Detailed discussionregarding the configuration of the body 12 and its three actuation wiresis provided in the aforementioned incorporated U.S. patent and patentapplication.

For a detailed discussion of one embodiment of the handle 14 of thesubject invention, reference is now made to FIG. 2, which is anisometric view of the handle 14 with the upper and lower grip portions24 a, 24 b separated and the first actuation mechanism 40 exploded tobetter illustrate its various components. As shown in FIG. 2, the gripportions 24 a, 24 b of the handle 14 are adapted to matingly couple witheach other and serve as an enclosure and mounting base for the first andsecond actuation mechanisms 40, 42 and the auto-locking mechanism, 54.The first actuation mechanism 40 is mounted in a distal portion of thehandle 14, and the second actuation mechanism 42 is mounted in aproximal portion of the handle 14. The electrical plug 26 is mounted ina proximal end assembly 46 that serves as the proximal end of the handle14.

As illustrated in FIG. 2, the first actuation mechanism 40 includes thefirst actuator 20, a gear assembly 48 with a cover 50, first and secondcontrol arms 52 a, 52 b, and an auto-locking mechanism 54. Theauto-locking mechanism 54 can assume any one of numerous formats, but isadapted to hold the distal end of the catheter in place withoutconscious and/or actual input from the operator, depending on theembodiment.

In catheter operation, the operator will manipulate one or more of thefirst or second actuators 20, 22, causing the distal end 18 to deflectfrom the original position as manufactured, or its zero position.Typically, the distal end 18 of the catheter is naturally biased toreturn toward its zero position, and accordingly exerts a pressure onthe first or second actuators 20, 22 through the actuation wires toreturn towards the zero position. In prior art devices this pressuremust be counteracted by the operator, either by holding the actuator(s)in place, or by manually setting a locking mechanism before or duringthe procedure. In the present invention, the auto-locking mechanismautomatically retains the distal end in the deflected state set by theoperator with no input from the operator, freeing the operator toperform other tasks.

As illustrated in FIG. 2, the auto-locking mechanism 54 pivotallycouples the first actuator 20 to the lower grip portion 24 b and caninclude one or more washers 56, a bushing 58 and a screw 60, e.g., ahex-head screw, for attaching the auto-locking mechanism 54 as anintegral unit to a pivot base 62 on the lower grip portion 24 b. Asshown in FIG. 2, each washer 56 can be a different size.

For a detailed discussion of the gear assembly 48, reference is now madeto FIG. 3, which is an exploded isometric view of the gear assembly 48.As shown in FIG. 3, the gear assembly 48 includes a frame 64, first andsecond pinion gears 66 a, 66 b, first and second wire blocks 68 a, 68 b,and the cover 50. The frame 64 includes a face plate 70, a base or floor71, and first and second stationary gear racks 72 a, 72 b. The first andsecond stationary gear racks 72 a, 72 b are fixed to the lateral sidesof the base 71 of the frame 64 and oriented such that their respectiveteeth sides 74 a, 74 b face each other and are generally parallel to thelongitudinal centerline of the frame 64. The face plate 70 is alignedwith the longitudinal centerline of the frame 64, positioned between thetwo stationary gear racks 72 a, 72 b, and generally perpendicular to thebase 71 of the frame 64. Each vertical side or face 75 a, 75 b of thefaceplate 70 is generally planar.

As indicated in FIG. 3, each wire block 68 a, 68 b includes a movablegear rack 76 a, 76 b, a generally planar vertically oriented face 77 a,77 b, and a hole 78 a, 78 b. Each movable gear rack 76 a, 76 b extendsdownwardly from its respective wire block 68 a, 68 b and has teeth 80 a,80 b on one side and a generally planar vertical face 77 a, 77 b on theother. The moveable gear racks 76 a, 76 b are oriented such that theyare generally parallel to each other, their teeth 80 a, 80 b face awayfrom each other, and their planar faces 77 a, 77 b face each other in agenerally parallel arrangement.

Each hole 78 a, 78 b is adapted to receive a proximal end of one of thefirst and second actuation wires. For example, as illustrated in FIG. 4,which is a top plan view of a first embodiment of the first actuationmechanism 40 mounted in the proximal portion of the lower grip portion24 b, the first and second actuation wires 81 a, 81 b are received intheir respective holes 78 a, 78 b upon exiting the proximal end 16 ofthe body 12.

As shown in FIG. 4, the actuator 20 is pivotally mounted to the lowergrip portion 24 b via the pivot assembly 54. The first actuationassembly 40 is located distal to the actuator 20 and proximal to the tothe strain relief 28. In one embodiment, the first actuator 20 includesa position indicator point 82 on its most distal edge and first andsecond openings 84 a, 84 b that are located on opposite lateral sides ofthe actuator 20.

As indicated in FIG. 4, a proximal end of a control arm 52 a, 52 bresides in each opening 84 a, 84 b. In a first embodiment of the firstactuation mechanism 48, as depicted in FIG. 4, the openings 84 a, 84 bare arcuate slots 84 a, 84 b that are substantially longer in lengththan the diameter of the control arm 52 a, 52 b.

As illustrated in FIG. 5, which is an enlarged plan view of the gearassembly 48 with the top portions of the wire blocks 68 a, 68 b removedto better illustrate the gearing arrangement, a distal end of a controlarm 52 a, 52 b resides in a hole 86 a, 86 b in each pinion gear 66 a, 66b. In one embodiment, each hole 86 a, 86 b is positioned at the axialcenter of its respective pinion gear 66 a, 66 b. In another embodiment,as depicted in FIG. 5, each hole 86 a, 86 b is offset from the axialcenter of its respective pinion gear 66 a, 66 b.

As shown in FIG. 6, which is a bottom plan view of the handle 14 withthe lower grip portion 24 b removed to reveal portions of the first andsecond actuation mechanisms 40, 42, each control arm 52 a, 52 b extendsbetween its respective points of connection with a hole 86 a, 86 b of apinion 66 a, 66 b and an opening 84 a, 84 b in the first actuator 20.Thus, as will be understood from FIGS. 4-6, the control arms 52 a, 52 bserve as linkages to transmit the motion of the first actuator 20 to thepinions 66 a, 66 b.

As illustrated in FIG. 5, each pinion gear 66 a, 66 b is positionedbetween, and engaged with, a stationary gear rack 72 a, 72 b and amoveable gear rack 76 a, 76 b. A generally planar back 77 a, 77 b ofeach moveable gear rack 76 a, 76 b slideably abuts against a respectivegenerally planar face 75 a, 75 b of the faceplate 70.

As shown in FIG. 5, in one embodiment, where the hole 86 a, 86 b in eachpinion 66 a, 66 b is offset from the pinion's axial center, when thepinion 66 a, 66 b is positioned at the most distal end of the stationarygear rack 72, 72 b, the hole 86 a, 86 b will be located immediatelyadjacent, and slightly distal to, the most distal tooth 88 a, 88 b ofthe respective stationary gear rack 72 a, 72 b. In one embodiment, toprevent the pinions 66 a, 66 b from over traveling relative to the gearracks 72 a, 72 b, 76 a, 76 b, a blank toothless section 90 a, 90 bexists along the circumference of each pinion 66 a, 66 b next to thepinion's hole 86 a, 86 b.

As shown in FIGS. 5 and 6, an arcuate slot 92 a, 92 b exists betweeneach pair of gear racks 72 a, 72 b, 76 a, 76 b in a base or floorportion 71 of the frame 64. Each arcuate slot 92 a, 92 b serves as apathway through which the distal portion of each control arm 52 a, 52 bmay pass as the respective pinion gear 66 a, 66 b displaces along thestationary gear rack 72 a, 72 b. The arcuate configuration of thearcuate slots 92 a, 92 b allows the distal parts of each control arm 52a, 52 b to follow the sinusoidal displacement of the holes 86 a, 86 bwhen the pinions 66 a, 66 b displace along the stationary gear racks 72a, 72 b.

Because the holes 86 a, 86 b are offset from the axial centers of thepinions 66 a, 66 b, a mechanical advantage is created as compared to aconfiguration where the holes 86 a, 86 b are centered at the axialcenters of the pinions 66 a, 66 b. The mechanical advantage results inan actuation force, as perceived by a user, that is less than and moreconstant than the actuation forces required to operate prior artcatheters.

The operation of the first embodiment of the first actuation mechanism40, wherein the each opening 84 a, 84 b is an arcuate slot 84 a, 84 b,will now be described while referencing FIGS. 4-6. As indicated in FIGS.4-6, when the first actuation mechanism 40 is in a neutral pivotalposition (i.e., when the wire blocks 68 a, 68 b are both in their mostproximal positions and the position indicator point 82 is facingdistally and is generally aligned with the longitudinal centerline ofthe lower grip portion 24 b, as depicted in FIG. 4), the proximal end ofeach control arm 52 a, 52 b is in the most distal portion of itsrespective arcuate slot 84 a, 84 b. This configuration of the firstembodiment of the first actuation mechanism 40 is advantageous where theactuation wires 81 a, 81 b are tension or pull type actuation wires.More specifically, it is advantageous where the actuation wires 81 a, 81b are only to be placed in tension and never to be compressed, therebyavoiding buckling of the actuation wires 81 a, 81 b.

For example, as can be understood from FIGS. 4-6, when the firstactuator 20 is pivoted in a first direction (e.g., counterclockwise FIG.4), the proximal end of the first control arm 52 a is engaged by thedistal end of the first arcuate slot 84 a and the first control arm 52 ais pulled proximally. This causes the distal end of the first controlarm 52 a to cause the first pinion gear 66 a to displace proximallyalong the corresponding stationary gear rack 72 a. The rotation of thefirst pinion gear 66 a causes the corresponding moveable gear rack 76 ato be driven proximally. As can be understood from FIG. 4, this causesthe corresponding wire block 68 a to place the first actuation wire 81 ain tension as the wire block 68 a proximally displaces.

While pivoting the actuator 20 in the first direction causes the firstwire block 68 a to act on the first actuation wire 81 a, such amovement, generally speaking, has no impact on the second wire block 68b or the second actuation wire 81 b. This is because a counter clockwiserotation of the actuator 20 simply causes the second arcuate slot 84 bto slide along the proximal end of the control arm 52 b without theproximal end of the second arcuate slot 84 b encountering the proximalend of the control arm 52 b. As a result, the first actuator 20 does notdistally drive the second control arm 52 b and the second wire block 68b is not caused to distally displace. Accordingly, the second actuationwire 81 b is not placed in tension or compression when the actuator 20is pivoted in the first direction (i.e., counterclockwise). In otherwords, the second actuation wire 81 b is allowed to relax and movefreely.

In one embodiment, when the actuator 20 is pivoted back to the neutralpivotal position depicted in FIG. 4, the proximal end of the firstarcuate slot 84 a does not encounter the proximal end of the firstcontrol arm 52 a. As a result, the first actuator 20 does not drive thefirst wire block 68 a and its corresponding actuation wire 52 a distallyback into the neutral position. Instead, the tension that the deflecteddistal end 18 exerts on the first actuation wire 52 a causes the wire 52a and its corresponding block 52 a to return to the neutral position.

Continuing the example, as can be understood from FIGS. 4-6, when thefirst actuator 20 is pivoted in a second direction (is., clockwise inFIG. 4), the proximal end of the second control arm 52 b is engaged bythe distal end of the second arcuate slot 84 b and the second controlarm 52 b is pulled proximally. This causes the distal end of the secondcontrol arm 52 b to cause the second pinion gear 66 b to displaceproximally along the corresponding stationary gear rack 72 b. Therotation of the second pinion gear 66 b causes the correspondingmoveable gear rack 76 b to be driven proximally. As can be understoodfrom FIG. 4, this causes the corresponding wire block 68 b to place thesecond actuation wire 81 b in tension as the wire block 68 b proximallydisplaces.

While pivoting the actuator 20 in the second direction causes the secondwire block 68 b to act on the second actuation wire 81 b, such amovement, generally speaking, has no impact on the first wire block 68 aor the first actuation wire 81 a. This is because a clockwise rotationof the actuator 20 simply causes the first arcuate slot 84 a to slidealong the proximal end of the control arm 52 a without the proximal endof the first arcuate slot 84 a encountering the proximal end of thecontrol arm 52 a. As a result, the first actuator 20 does not distallydrive the first control arm 52 a and the first wire block 68 a is notcaused to distally displace. Accordingly, the first actuation wire 81 ais not placed in tension or compression when the actuator 20 is pivotedin the second direction (i.e., clockwise). In other words, the firstactuation wire 81 a is allowed to relax and move freely.

In one embodiment, when the actuator 20 is pivoted back to the neutralpivotal position depicted in FIG. 4, the proximal end of the secondarcuate slot 84 b does not encounter the proximal end of the secondcontrol arm 52 b. As a result, the first actuator 20 does not drive thesecond wire block 68 b and its corresponding actuation wire 52 bdistally back into the neutral position. Instead, the tension that thedeflected distal end 18 exerts on the second actuation wire 52 b causesthe wire 52 b and its corresponding block 52 b to return to the neutralposition.

As can be understood from FIGS. 4 and 5, because of the gearingarrangement, the proximal linear displacement of a moveable gear rack 76a, 76 b and, as a result, its corresponding actuation wire 81 a, 81 b isgenerally twice the proximal linear displacement of the correspondingpinion gear 66 a, 66 b. This is because the proximal displacement of amoveable gear rack 76,76 b is the sum of a pinion gear's linear proximaldisplacement along a stationary gear rack 72 a, 72 b plus the piniongear's rotational displacement.

For a discussion of a second embodiment of the first actuation mechanism40, reference is now made to FIGS. 7-9. FIGS. 7-9 are, respectively, thesame views depicted in FIGS. 4-6, except of the second embodiment of thefirst actuation mechanism 40. Generally speaking, the features of thefirst and second embodiments of the first actuation mechanism 40 are thesame, except as provided in the following discussion.

As shown in FIG. 7, unlike the arcuate slots 84 a, 84 b of the firstembodiment of the actuation mechanism 40 (as discussed in reference toFIGS. 4-6), the openings 84 a, 84 b of the second embodiment arecircular holes 84 a, 84 b with diameters generally equal to the diameterof the control arms 52 a, 52 b. As indicated in FIG. 7, a proximal endof a control arm 52 a, 52 b resides in each circular opening 84 a, 84 b.

As can be understood from FIGS. 7-9, in the second embodiment of theactuation mechanism 40, when the first actuation mechanism 40 is in aneutral pivotal position (i.e., the position indicator point 82 isfacing distally and generally aligned with the longitudinal centerlineof the lower grip portion 24 b, as depicted in FIG. 7), each pinion 66a, 66 b is positioned approximately midway along both of the lengths ofits respective stationary gear rack 72 a, 72 b and moveable gear rack 76a, 76 b. This arrangement allows the control arms 52 a, 52 b tooppositely and equally move relative to each other when the actuator 20is pivoted. This movement is brought about in the second embodiment ofthe first actuation mechanism 40 because, unlike the arcuate slots 84 a,84 b of the first embodiment, the circular openings 84 a, 84 b of thesecond embodiment prevent displacement between the proximal ends of thecontrol arms 52 a, 52 b and the actuator 20. The configuration of thesecond embodiment of the first actuation mechanism 40 is advantageouswhere the actuation wires 81 a, 81 b are pull/push ortension/compression type actuation wires.

For example, as can be understood from FIGS. 7-9, when the firstactuator 20 is pivoted in a first direction (e.g., counterclockwise inFIG. 7), the proximal end of the first control arm 52 a is pulledproximally by the first circular opening 84 a, and the proximal end ofthe second control arm 52 b is pushed distally by the second circularopening 84 b. Accordingly, the distal end of the first control arm 52 apulls the first pinion gear 66 a proximally along its correspondingstationary gear rack 72 a, and the distal end of the second control arm52 b pushes the second pinion gear 66 b distally along its correspondingstationary gear rack 72 b. The rotation of the first pinion gear 66 aproximally drives its corresponding moveable gear rack 76 a, and therotation of the second pinion gear 66 b distally drives itscorresponding moveable gear rack 76 b. As can be understood from FIG. 7,this causes the first wire block 68 a to place the first actuation wire81 a in tension as the wire block 68 a proximally displaces. Also, thiscauses the second wire block 68 b to push (i.e., compress) the secondactuation wire 81 b distally as the second wire block 68 b distallydisplaces.

As can be understood from FIGS. 7-9, pivoting the first actuator 20 in asecond direction (i.e., clockwise) reverses the movement of the controlarms 52 a, 52 b. Accordingly, the second wire block 68 b movesproximally (i.e., the second actuation wire 81 b is placed intotension), and first wire block 68 a moves distally (i.e., the firstactuation wire 81 a is compressed or released).

For a detailed discussion of one embodiment of the second actuationmechanism 42, reference is now made to FIG. 10, which is an isometricview of the handle 14 with the upper and lower grip portions 24 a, 24 bseparated and the second actuation mechanism 42 exploded to betterillustrate its various components. As shown in FIG. 10, the secondactuation mechanism 42 is mounted in a proximal portion of the handle 14and includes a second actuator 100 with upper and lower arms 102 a, 102b, the upper and lower buttons 22 a, 22 b of the second actuator 100, apivot assembly 104, upper and lower pins 106 a, 106 b, a lever 108, anda slide block 110.

As illustrated in FIG. 10, the actuation handle 14 can include a secondactuation mechanism 22 with upper and lower buttons 22 a, 22 b. Thesecond actuation mechanism includes a second actuator 100 that isgenerally U-shaped. The second actuator's arms 102 a, 102 b aregenerally vertically aligned and offset from each other in a parallelarrangement to form a gap 103 through which the proximal portion of thefirst actuator 20 displaces. The lower arm 102 b slideably resides in alongitudinal slot or groove 113 in the lower grip portion 24 b.Similarly, the upper arm 102 a slideably resides in a longitudinal slotor groove in the upper grip portion 24 a.

As shown in FIG. 10, each arm 102 a, 102 b includes a head 112 a, 112 bwith a pinhole 114 a, 114 b for receiving a pin 106 a, 106 b. The upperhead 112 a extends through a longitudinal slot 115 in the upper gripportion 24 a to couple to the upper button 22 a. Similarly, the lowerhead 112 b extends through a longitudinal slot in the lower grip portion24 b to couple to the lower button 22 b. The lower head 112 b resides ina seat 117 in the lower button 22 b and is coupled thereto via the pin106 b. Likewise, the upper head 112 a resides in a seat in the upperbutton 22 a and is coupled thereto via the pin 106 a. Because eachbutton 22 a, 22 b is coupled to an arm 102 a, 102 b of the secondactuator 100, the buttons 22 a, 22 b are slaved together.

As indicated in FIG. 10, the heads 112 a, 112 b are slideablydisplaceable within their respective longitudinal slots 115. Thus, whena user slides the buttons 22 a, 22 b longitudinally relative to the gripportions 24 a, 24 b to actuate the second actuation assembly 42, thearms 102 a, 102 b and heads 112 a, 112 b slideably displace in theirrespective slots 113, 115.

As shown in FIG. 10, the lever 108 is pivotally coupled to a pivot base118 in the lower grip portion 24 b via the pivot assembly 104. The pivotassembly 104 includes a series of washers 120 (including a Bellevillespring washer to compensate for compression set or material creep duringthe catheter's shelf life), and a hex-head screw 124 for securing thepivot assembly 104 to the pivot base 118 as one integral unit. When thehex-head screw 124 is properly tightened, the pivot assembly 104 isconfigured such that it acts as an auto-locking mechanism 54 byproviding a tension drag feature that holds the lever 108 in placealthough the user has released the buttons 22 a, 22 b. As a result, theuser does not need to maintain contact with the buttons 22 a, 22 b tomaintain the distal end 18 in a set position once placed there by theuser actuating the second actuation mechanism 42.

As illustrated in FIG. 10, in one embodiment, the lever 108 is generallysemicircular such that it has a generally linear edge 119 and agenerally arcuate edge 121 extending between the first and second endsof the linear edge 119. The linear edge 119 is adjacent the pivotassembly 104 and faces generally distally. In one embodiment, the radiusof the arcuate edge 121 is generally equal to the distance between thearcuate edge 121 and the axis of the pivot assembly 104. The arcuateedge 121 faces generally proximally.

For further discussion of the components of the second actuationmechanism 42, reference is now made to FIG. 11, which is a top plan viewof the second actuation mechanism 42 mounted in the lower grip portion24 b with the upper grip portion 24 a removed. As indicated in FIG. 11,a bottom end of the slide block 110 is slideably received in a lowergroove or slot 128 in the lower grip portion 24 b. Similarly, a top endof the slide block 110 is slideably received in an upper groove or slotin the upper grip portion 24 a. The slots 128 are generally parallel tothe longitudinal axis of the handle 14.

As illustrated in FIG. 11, a third actuation wire 129 extends from thedistal end 18 of the body 12 and into the handle 14 to couple the slideblock 110. In one embodiment, the third actuation wire 129 also servesas an electrical wire leading from one or more electrodes 30 in thedistal tip 18 to the electrical plug 26 in the proximal end of thehandle 14. In doing so, the third actuation wire 129 passes through, andcouples to, the slide block 110.

As shown in FIG. 11, a threaded rod 130 extends between a proximal sideof the slide block 110 and a clevis 132 pivotally attached to a firstend of the lever 108 via a pin 109. The threads on the threaded rod 130allow the distance between the clevis 132 and the slide block 110 to beadjusted. Thus, the initial actuation wire position relative to thelever 108 can be adjusted via the threaded rod 130.

As indicated in FIG. 11, an arm 134 extends from the proximal end of thesecond actuator 100 in a direction opposite from the slide block 110. Alink 136 is pivotally coupled to an end of the arm 134 via a pin 138. Acable 140 is coupled to the link 136 and extends to and around thearcuate side 121 of the lever 108 to couple to the lever 108 via anattachment feature 142 (e.g., a screw, bolt, pin, etc.). The arcuateside 121 of the lever 108 is grooved or slotted to receive the cable140. The cable 140 and arcuate side 121 of the lever 108 operatetogether like a belt and pulley such that a moment arm between the cable140 and the pivotable lever 108 remains constant as the lever 108pivots.

As can be understood from FIG. 11, when actuating the third actuationwire 129 to cause the distal end 18 of the body 12 to deflect, a userdisplaces a button 22 a, 22 b distally, which causes the U-shaped secondactuator 100 to displace distally. As a result, the arm 134 pulls thecable 140 distally, thereby causing the lever 108 to pivot in acounterclockwise direction about the pivot assembly 104. This pivotingmovement causes the clevis 132 to pull the slide block 110 in a proximaldirection. The proximal movement of the slide block 110 places the thirdactuation wire 129 into tension (i.e., it pulls the third actuation wire129), which causes the distal end 18 of the body 12 to deflect.

Increasingly deflecting the distal end of the body 12 requires anincreasing force. Thus, during the initial stages of distal enddeflection of the body 12, the force needed to pull the third actuationwire 129 is lower than at the final stages of distal end deflection. Theincreasing force needed to further increase the deflection of the distalend of the body 12 is addressed by the configuration between the clevis132 and the lever 108. Specifically, the configuration between theclevis 132 and the lever 108 is such that the moment arm changes as thelever 108 pivots.

The moment arm length between the clevis 132 and the pivot assembly 104of the lever 108 is greatest during the initial stages of distal tipdeflection (i.e., when the pin 109 is at its most distal position).Because of the configuration between the clevis 132 and the lever 108,the length of the moment arm decreases as the distal end 18 isincreasingly deflected (i.e., the pin 109 moves proximally).Consequently, the mechanical advantage at the buttons 22 a, 22 b is theleast when the actuation wire tension is low (i.e., during the initialstages of distal end deflection) and the most when the actuation wiretension is high (i.e., during the last stages of distal end deflectionapproaching full deflection).

As can be understood from FIG. 11, to allow the deflected distal end 18to return to its non-deflected configuration, a user proximallydisplaces a button 22 a, 22 b, which causes the U-shaped second actuator100 to proximally displace. This provides slack in the cable 140, whichallows the lever 108 to pivot clockwise as the spring force stored inthe deflected distal end 18 acts to distally pull the third actuationwire 129 and, as a result, the slide block 110 as the distal end 18springs back into a non-deflected configuration.

In use, the body 12 of the catheter 10 is inserted into the patient in amanner well known in the art. An operator grasps the handle 14 andmanipulates the first actuator 20 between his thumb and finger.Advantageously, the first actuator 20 protrudes from each side of thehandle 14 to allow for such ease of movement and manipulation. The firstactuator 20 is moved relative to the handle 14, which causes the firstand second actuation wires 78 a, 78 b to be displaced via the firstactuation mechanism 40. As a result, the distal end 18 of the body 12deflects.

To deflect the distal end 18 of the body 12 in another manner, the userdistally slides the buttons 22 a, 22 b with a thumb or finger. Thiscauses the third action wire 129 to displace via the second actuationmechanism 42. As a result, the distal end 18 of the body 12 deflects inmanner different from the deflection brought about by the actuation ofthe first actuation mechanism 40. For example, the displacement of thethird action wire 129 may bring about a deflection of the distal endinto any curvilinear shape, such as a loop, a spiral, or into an sshape. In addition, the distal end may be preformed into any curvilinearshape, including a loop, a spiral, or an s-shape, and the displacementof the third action wire may bring about a widening or narrowing of thecurvilinear shape. Likewise, the first and second action wires 78 a, 78b can bring about a deflection in a first plane, and the third actionwire 129 may bring about a deflection in a second plane, e.g., a planeperpendicular to the first plane.

In another embodiment, as illustrated in FIG. 2, an auto-lockingmechanism 54 pivotally couples the first actuator 20 to the lower gripportion 24 b and can include one or more washers 56, a bushing 58 and ascrew 60, e.g., a hex-head screw, for attaching the auto-lockingmechanism 54 as an integral unit to a pivot base 62 on the lower gripportion 24 b. As shown in FIG. 2, each washer 56 can be the same ordifferent.

As will be appreciated by one of ordinary skill in the art, the bushing58 can be constructed of any of a number of materials, includingcommonly available polymers, e.g., PEEK, polysulfone, etc., metals,e.g., stainless steel, brass, etc., or other materials. The washers 56can be any commonly available form, including flat washers or wavewashers and constructed of stainless steel, brass, or a polymericmaterial. The screw 60 can be any type of screw, bolt, or connectionmeans, including, preferably, a hex-head screw. The pivot base 62 can beconstructed of the same or different materials as the lower grip portion24 b. The pivot base 62 can be constructed integrally with the lowergrip portion 24 b, or it can be a separate piece that is glued, weldedor otherwise attached to lower grip portion 24 b.

As shown in FIGS. 2, 12 and 12A, in operation a washer 56 is optionallyplaced on the landing 62 a. The actuator 20 is then placed over thepivot base 62 and onto the washer 56 or the landing 62 a. An optionalwasher 56 can be placed on the actuator 20. The bushing 58 is threadedthrough the washers 56, actuator 20, and pivot base 62. A hex-head screw60 is then threaded through the bushing 58, the washers 56, the actuator20, and is tightened into the pivot base 62. It is preferable that thebushing 58 fit closely over the pivot base 62 so as to prevent excessivelateral motion between the bushing 58 and the pivot base 62 duringrotational motion of the actuator 20. Likewise, it is preferable thatthe actuator 20 fit closely over the bushing 58 to prevent lateralmotion between the bushing 58 and the actuator 20 during rotationalmotion of the actuator 20.

The screw 60 will be tightened during manufacturing to create a tensionT. T is determined by considering several factors, and will vary fromapplication to application, but must be a sufficient tension tocounteract the distal end's bias towards its zero position. At the sametime, if T is too large the operator will be forced to exert greatpressure to actuate the catheter, which is undesirable. Typicalcommercially available catheters today require 2-10 pounds of thumbforce from the operator on the actuation handle to deflect the distalend in a desired direction. For example, a catheter may require 3 poundsof thumb force. In such a case, depending on the catheter construction,the deflected distal end 18 may exert 2-3 pounds of force towards itsneutral or zero position. Accordingly, the tension T is set sufficientlylarge to counteract that force, e.g., 3 or more pounds. The tension Tcan also be increased as necessary to give the catheter operation adesirable level of thumb force for the operator, as increasing thetension T will increase the thumb force required to operate thecatheter. Once the screw 60 has been tightened to create the desiredtension T, the screw 60 can be permanently or semi-permanently fixed inplace by application of a locking fluid.

The bushing 58 can have notches 58 a cut in its bottom portion that aredesigned to mate with slats 62 b. The slats 62 b are located in thespace between the pivot point 62 and the landing 62 a. When the notches58 a are joined to the slats 62 b the bushing 58 is engaged such thatthe bushing 58 will have little rotation relative to the lower gripportion 24 b, and as such the actuator 20 will have reduced “slack” tobe taken up by the operator before the distal end will deflect in thedesired direction. In a preferred embodiment, the bottom of the bushing58 can have cross hatching or other patterns cut onto its outer surfaceto facilitate mating with, or bonding to the inside of the landing 62 a.

As shown in FIGS. 12B and 12C, the auto-locking mechanism can furtherinclude a tensioning member 200. For example, as shown in FIG. 12B, aBelleville washer 202 can be placed between the bushing 58 and theactuator 20. As shown in FIG. 12C, a Belleville washer 204 can be placedbetween the landing 62 a and the actuator 20.

In operation, the components of the auto-locking mechanism may swell orshrink due to excessive heat or cold. The tensioning member 200 willoperate to either take up the slack, or to provide room for expansion,while at the same time maintaining a constant tension T. Thisadvantageously ensures that the operator will experience the samedesirable level of thumb force to operate the actuators as set duringmanufacturing. Such a tensioning member could be a Belleville washer asshown in FIGS. 12B, 12C, or another tensioning apparatus. In addition tothe locations shown in FIGS. 12A-12C, above, the tensioning member 200can be placed at any other point in the auto-locking mechanism 54 whereit will provide for a constant tension.

For example, as shown in FIG. 13A, a tensioning member such as a spring210 can be placed in a gap between landing 62 a and pivot point 62. Thebushing 58 can slip over the pivot point 62 and rest an optional washer56 that rests on the spring 210. As with a Belleville washer, the springcan be located in a variety of locations, so long as it provides for arelatively constant tension T on the actuator 20 to keep a constantthumb force for moving and automatically locking the actuator 20. Asshown in FIG. 13B, the spring 212 can be located between washer 56 andactuator 20, or as shown in FIG. 13C, the spring 214 can be locatedbetween the screw 60 and the bushing 58.

FIG. 14 depicts another variation of the invention, in which a bushing224 includes notches 224 a cut in its bottom portion that are designedto mate with slats 62 b. The slats 62 b are located in the space betweenthe pivot point 62 and the landing 62 a. When the notches 224 a arejoined to the slats 62 b the bushing 224 is engaged such that thebushing 224 will have little rotation relative to the lower grip portion24 b, and as such the actuator 220 will have reduced “slack” to be takenup by the operator before the distal end will deflect in the desireddirection. In a preferred embodiment, the bottom of the bushing 224 canhave cross hatching or other patterns cut onto its outer surface tofacilitate mating with, or bonding to the inside of the landing 62 a.The bushing 224 can be epoxied to the pivot point 62 and/or the landing62 a.

The bushing 224 can be constructed from any material, especially adurable polymer, a stainless steel, or brass. Ideally the materialselected will be sufficiently durable to endure long periods of sittingunder compression tension, and also have a low frictional range allowingready movement between the bushing 224 and the actuator components.

The bushing 224 may also have a D-shaped top surface 232. The bushingincludes a bushing landing surface 234 that rests on the landing 62 a.The bushing landing surface 234 and the sides of the bushing 224 may bepolished, e.g., to 8 microns, to maintain cycle durability. The actuator220 includes an integral actuation washer portion 222. The actuator 220is slid over the bushing 224. A D-shaped washer 226 is then mated withthe D-shaped top surface 232. A washer 228 rests between on the D-shapedwasher 226. A nut 230 is then attached to threaded surface 236 andtightened to a tension T, e.g., 5-6 pounds of force, and a drop ofthread lock is added.

In this aspect of the invention, the vertical load path advantageouslyruns only from bushing 224, its landing 234, through actuator 220 toD-shaped washer 226, optional washer 228, and nut 230. In particular,the load path does not include the polycarbonate upper or lower gripportions 24 a, 24 b, and thus does not place a long term stress on theseportions.

As shown in FIG. 15, the washer 228 may be replaced by a tensioningmember such as a Belleville washer 240. Likewise, as shown in FIGS. 15A,15B, a tensioning member such as a spring 242 or 244 may be employed. Asdetailed above, the tensioning member will operate to either take up theslack, or to provide room for expansion, while at the same timemaintaining a constant tension T. In addition to the locations shown inFIGS. 15-15C, above, the tensioning member can be placed at any otherpoint in the auto-locking mechanism 54 where it will provide for aconstant tension.

As shown in FIG. 16, an actuator 250 can include a post 258 designed toattach to upper and lower grip portions 24 a, 24 b by sliding over orotherwise attaching to pivot base 62 on lower grip portion 24 b andpivot base 262 on upper grip portion 24 a. Actuator 250 includes a firstpost 252 attached to a spring 256, e.g., a tension spring or extensionspring. The spring 256 is attached to a second post 254, which isattached to lower grip portion 24 b. In operation, as the actuator 250is pivoted on post 258, the distal end 18 of the catheter is deflected,and will exert a force F toward returning to the distal end's zeropoint. The spring 256, actuator 250, post 252, and post 254 are placedsuch that the spring is at its longest when the actuator is at itsmiddle point. When the actuator 250 is pivoted away from its middlepoint, the length between posts 252, 254 is shortened, thus shorteningthe spring 256. Thus, to return to the actuator 250's middle point, aforce F1 must be exerted to lengthen the spring 256. This force F1 willoppose the force F, and preferably exceed the force F. That is, theforce F generated by the distal end 18 seeks to return the distal end 18to its zero point, and thus return the actuator 250 to its middle point.The Force F1 generated by the spring 256 seeks to move the actuatorfurther to the left or right of its middle point, and thus move thedistal end to the left or right. As a result, the spring 256 acts as atensioning member 200 in the auto-locking mechanism. As is known to oneor ordinary skill in the art, the motion of the actuator 250, spring256, and posts 252, 254 may be aided by means of gears placed inrelation to the post to lengthen or shorten the distance between theposts 252, 254 during motion of the actuator 250.

The actuator of the present invention may assume numerous physicalformats, and is not limited to an actuator of the shape shown in thedrawings. For example, the actuator 20 could assume a T-shape, or couldbe round. As shown in FIG. 17, an actuator 280 can include a post 288designed to attach to upper and lower grip portions 24 a, 24 b bysliding over or otherwise attaching to pivot base 62 on lower gripportion 24 b and pivot base 262 on upper grip portion 24 a. The actuator280 may have depressible levers 284, 282, which must be depressed by theoperator in order for actuator 280 to pivot. The levers 284, 282 areconnected to a locking mechanism inside the actuator 20 that must bereleased before rotational motion is possible.

As shown in FIG. 18, a rotatable post 290 may be in frictional contactwith actuator 292 on post 294. In operation, as the actuator 292 ispivoted on post 294, the distal end 18 of the catheter is deflected, andwill exert a force F toward returning to the distal end's zero point.The rotatable post 290 must overcome a force F2, e.g., a frictionalforce, to rotate. Accordingly, the force F2 counteracts, and preferablyexceeds, the force F exerted by the distal end 18. As a result, therotatable post 290 acts as a tensioning member 200 in the auto-lockingmechanism.

Although embodiments of this invention have been described above with acertain degree of particularity, those skilled in the art could makenumerous alterations to the disclosed embodiments without departing fromthe spirit or scope of this invention. The actuator of the presentinvention may assume numerous physical formats, and is not limited to anactuator of the shape shown in the drawings. For example, the actuator20 could assume a T-shape, or could be round.

All directional references (e.g., upper, lower, upward, downward, left,right, leftward, rightward, top, bottom, above, below, vertical,horizontal, clockwise, and counterclockwise) are only used foridentification purposes to aid the reader's understanding of the presentinvention, and do not create limitations, particularly as to theposition, orientation, or use of the invention. Joinder references(e.g., attached, coupled, connected, and the like) are to be construedbroadly and may include intermediate members between a connection ofelements and relative movement between elements. As such, joinderreferences do not necessarily infer that two elements are directlyconnected and in fixed relation to each other. It is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative only and not limiting.Changes in detail or structure may be made without departing from thespirit of the invention as defined in the appended claims.

What is claimed is:
 1. A handle for use with a catheter, the handlecomprising: a grip portion having a longitudinally-extending centerline;an actuator pivotably coupled to the grip portion such that the actuatorcan be pivoted from a neutral position relative to the grip portion; apinion gear disposed within the grip portion; a gear rack disposedwithin the grip portion, wherein the gear rack comprises: a first,stationary gear rack; and a second, movable gear rack, and wherein thepinion gear is positioned between and engaged with the first, stationarygear rack and the second, movable gear rack; and a control arm, having aproximal end and a distal end, disposed within the grip portion, whereinthe proximal end of the control arm is mechanically engaged with theactuator and the distal end of the control arm is mechanically engagedwith the pinion gear at a point laterally offset from the centerline ofthe grip portion such that the control arm transmits motion of theactuator to the pinion gear.
 2. The handle according to claim 1, whereinthe actuator further comprises a slot and the proximal end of thecontrol arm resides in the slot.
 3. The handle according to claim 2,wherein the slot is arcuate.
 4. The handle according to claim 1, whereinthe grip portion comprises a slot and the distal end of the control armresides in the slot.
 5. The handle according to claim 4, wherein theslot is arcuate.
 6. The handle according to claim 1, wherein the piniongear is positioned at a distal end of the gear rack when the actuator ispositioned in the neutral position.
 7. The handle according to claim 1,further comprising an actuation wire coupled to the gear rack such thatmovement of the actuator is mechanically transmitted to the actuationwire through the control arm, the pinion gear, and the gear rack.
 8. Ahandle for use with a catheter, the handle comprising: a grip portionhaving a longitudinally-extending centerline; an actuator pivotablycoupled to the grip portion such that the actuator can be pivoted from aneutral position relative to the longitudinally-extending centerline ofthe grip portion; a first actuating assembly disposed within the gripportion on a first lateral side of the centerline of the grip portion,the first actuating assembly comprising: a first pinion gear having anaxial center; a first gear rack; and a first control arm having aproximal end and a distal end; and a second actuating assembly disposedwithin the grip portion on a second lateral side of the centerline ofthe grip portion, the second actuating assembly comprising: a secondpinion gear having an axial center; a second gear rack; and a secondcontrol arm having a proximal end and a distal end, wherein the proximalend of the first control arm is mechanically engaged with the actuatorand the distal end of the first control arm is mechanically engaged withthe first pinion gear at a point radially offset from the axial centerof the first pinion gear such that the first control arm transmitsmotion of the actuator in a first direction relative to the centerlineof the grip portion to the first pinion gear, and wherein the proximalend of the second control arm is mechanically engaged with the actuatorand the distal end of the second control arm is mechanically engagedwith the second pinion gear at a point radially offset from the axialcenter of the second pinion gear such that the second control armtransmits motion of the actuator in a second direction relative to thecenterline of the grip portion to the second pinion gear.
 9. The handleaccording to claim 8, wherein the actuator comprises a first arcuateslot and a second arcuate slot opposite the first arcuate slot, andwherein the proximal end of the first control arm resides in the firstarcuate slot and the proximal end of the second control arm resides inthe second arcuate slot.
 10. The handle according to claim 9, wherein,when the actuator is in the neutral position, the proximal end of thefirst control arm is positioned adjacent a distal end of the firstarcuate slot and the proximal end of the second control arm ispositioned adjacent a distal end of the second arcuate slot.
 11. Thehandle according to claim 9, wherein the grip portion comprises a firstarcuate slot and a second arcuate slot opposite the first arcuate slot,and wherein the distal end of the first control arm resides in the firstarcuate slot and the distal end of the second control arm resides in thesecond arcuate slot.
 12. The handle according to claim 11, wherein, whenthe actuator is in the neutral position, the distal end of the firstcontrol arm is positioned adjacent a distal end of the first arcuateslot and the distal end of the second control arm is positioned adjacenta distal end of the second arcuate slot.
 13. The handle according toclaim 8, wherein the first gear rack comprises a first stationary gearrack and a first movable gear rack and the second gear rack comprises asecond stationary gear rack and a second movable gear rack.
 14. Thehandle according to claim 13, wherein the first pinion gear ispositioned between and engaged with the first stationary gear rack andthe first movable gear rack and the second pinion gear is positionedbetween and engaged with the second stationary gear rack and the secondmovable gear rack.
 15. The handle according to claim 8, wherein, whenthe actuator is in the neutral position, the first pinion gear ispositioned adjacent a distal end of the first gear rack and the secondpinion gear is positioned adjacent a distal end of the second gear rack.16. The handle according to claim 8, wherein the first actuatingassembly comprises a first actuation wire coupled to the first gear rackand the second actuating assembly comprises a second actuation wirecoupled to the second gear rack.